While there is no shortage of security apps on the Play Store, aeGis one stands out a bit for a few reasons. For starters, it's dead simple to use. Set up a specific trigger phrase and you can text your phone to lock the display, remotely wipe, find the address of, or sound an alarm from your phone. There's no web interface, unfortunately, but this app trades the elaborate suite of services of something like Avast for simplicity.